Wind energy is the world's fastest growing energy source and is already a major source of energy across Europe. By the end of 2002, Europe was producing approximately 75% of the world's total wind energy, while Canada produced only 0.4% (Jacob, 2003). Technological advancements over the last 25 years have resulted in significant reduction in the cost of wind generated energy from 38 US cents (per kWh) in 1982 to between 4 and 6 US cents (per kWh) in 2001 (Jacob, 2003). According to Marsh (2001), this dramatic decrease is mainly due to the use of composite materials for the construction of lighter rotor blades. Indeed, composite materials are slowly finding their way into more and more applications in wind generator nacelles, cabins, fairings and parts of towers. Industry estimates suggest that 80,000 tons of finished composites will be required annually by 2005 for rotor blades alone.
Composite materials have the potential to decrease the total weight of the wind towers, leading to substantial saving in transportation and erection costs, making wind energy more affordable for remote and rural communities where the number of s required is usually small. In a white paper published by WindTower Composites (2003), it was reported that the cost of composite towers, based on a 2-unit wind farm, is 38% less than the cost of steel towers. For a 25-unit wind farm, the cost of composite towers is 28% less than steel towers. Thus, even though the cost of composite materials per unit weight is higher than that of steel, the lower total weight of composite towers compared to steel, results in lower transportation and erection costs. Furthermore, the cost advantage for steel has been eroding over the last year as the price of steel in the world market has increased, while the cost of composite materials has been steadily decreasing. As a result, research in the development of composite wind towers has begun in earnest both in the United States and Europe (DOE, 2003; CORDIS, 2003).
The use of wind energy in rural communities will often provide significant economic advantages over conventional power generating systems. For example, Cambridge Bay, Nunavut is a community of about 1,200 people, located on the south shore of Victoria Island in the Canadian Arctic. Electrical power is provided by diesel shipped in from Hay River by barge in the summer. The results from an NRCan study, indicate that conversion to wind power would displace about 300,000 liters of fuel per year. At 1999 fuel prices, this translates to an annual saving of $258,000 in fuel costs.
The application of composite wind towers, however, is not limited to remote areas. As the cost of steel continues to rise and as towers become larger, high materials costs, coupled with high transportation and erection costs, makes composite materials more attractive for the construction of small wind farms.
As a result, there has been a need for the construction of lightweight and more durable wind towers made of composite materials where transportation and erection problems make the use of heavy equipment difficult and in offshore regions where corrosion is of major concern.